Method for treatment of materials



July 26, 1938. w. J. PLEWS 2,124,743"

METHOD FOR TREATMENT'OF MATERIALS Filed Dec. 17, 1934 4 Sheets-Sheet 1 July 26, 1938. w. J. PLEWS METHOD FOR TREATMENT OF MATERIALS 4 Sheets-Sheet 2 Filed Dec. 17, 1934 July 26, 1938. w. .1. PLEWS METHOD FOR TREATMENT of MATERIALS Filed Dec. '17. 1954 4 Sheets-Sheet s Jul 26, 1938. w. .1. PLEWS METHODF'OR TREATMENT OF MATERIALS Filed Dec. 17, 1954 {1 Sheets-Sheet 4 Patented July 26, 1938- METHOD FOR TREATMENT OF MATERIALS William J. Plcws, Niagara Falls, N. Y., assignor to Plcws Processes, Inc., a. corporation of New York Application December 17, 1934, Serial No. 757,964

Claims.

The present invention relates to a'method of treating materials, and the product of said method, and more particularly to a method of subjecting materials to the sudden pressure reduction or explosion process.

Broadly, the invention consists in the provision of a method whereby the material to be treated is placed in a closed vessel to which a heating medium is supplied in a particular manner, and permitted to remain therein for a predetermined period of time, after which the pressure in said receptacle is suddenly released in a novel manner, whereby the material is violently expelled from the receptacle.

I am aware that it is not new to subject materials such as wheat, rice and other starchy fibrous and/or crystalline substances, to a fluid under pressure in a closed vessel and suddenly release the pressure to puff, distintegrate, dehydrate, or otherwise change the physical and chem-- ical properties of the same.

For example, one method commonly employed heretofore for pufling cereal grains consists in placing'the grains to be pufied in a chamber or gun, raising the temperature and pressure within the gun by the application of external heat, rotating the gun during the heating operation, and subsequently suddenly reducing the pressure within the gun to expel the grains therefrom in the pufied condition. The time required for the heating operation is usually from thirty to fortyfive minutes. During the heating operation the temperature of the wall of the gun is at all times considerably higher than that prevailing within the gun. In the'treatment of cereal grains having a relatively high fat content, as for example oat groats, a partial decomposition of the fat content occurswhen the grains are brought in contact with the inner surface of the chamber wall because of the high temperature of the latter. The resultant product will 'be extremely sensitive to the development of rancidity.

The method forming the subject-matter of the present invention, while of general application, is ideally suited to the putting of oat groats, and will be described in connection therewith, but I wish it distinctly understood that the description is for purposes of illustration only and is' not to be construed as in any way limiting the scope of the invention.

An object of my invention is to provide a.

method by which cereal grains having a. relatively high fat content may be treated without danger of decomposing the fat content thereof to produce an extremely stable product which may be kept for an indefinite period of time without development of rancidity.

A further object of my invention is to provide a method of pufling cereal grains which results in a product, the individual grains of which are of substantially uniform size.-

A further object of my invention is to provide a novel method for completely expelling from a pressure chamber material undergoing treatment therein upon sudden reduction of the pressure in the chamber. A further object of my invention is to provide a novel method for preventing damage to the material undergoing treatment by the medium employed for raising the temperature and pressure within the treating chamber.

A further object of my invention is to providev a novel food product.

Other objects, features and advantages will appear as the description proceeds.

In the accompanying drawings- Figure 1 is a perspective view of a device whereby my present invention may be practiced.

Figure 2 is a side 'elevational view thereof in section.

Figure 3 is a perspective view, partly in section, of a portion of the mechanism adapted to coact with the valve closure member of the treating chamber.

Fi ure 4 is a side elevational view of the device of Fig. 1.

Figure 5 is a fragmentary plan view of the pressure chamber partly in section.

Figure 6 is a perspective view of one type of diffusion member.

- Figure 7 is an elevational view of the device of Fig. 1, and

Figure 8 is a fragmentary sectional view of certain details.

In carrying out my invention, the oat groats are placed in a treating chamber which is then closed and a fluid under pressure and at an elevated temperature is admitted'thereto, the fluid, however, being difi'used before it comes in contact with the groats. Preferably this may be accomplished by providing a perforated baflle or partition within the chamber, but any suitable manner for efiecting diffusion of the incoming fluid may be employed, the important point being to eliminate a concentrated application of the fluid to any portion of the mass undergoing treatment. Preferably the chamber is provided with a vent or other means to permit the air contained therein to escape as the fluid enters- It is desirable that all of the air be removed from the chamber to prevent the formation of air pockets which are detrimental to the successful treatment of that portion of the mass lying in the zone ofthe pocket.

After the greats have remained in the chamber for the necessary period of time, the pressure therein is suddenly released, as by releasing a closure member at one end of the chamber, and the groats are forcibly discharged from the chamber in the puffed condition.

An important feature of my invention isthe application, at the instant of discharge, of a secondary supply of fluid medium moving in the same direction as the oat groats. The effect of so doing is two-fold. First, the fluid medium so applied serves in a degree to maintain the pressure differential between the interior and exterior of the individual grains at a minimum until the grains reach the atmosphere, when the full advantage of substantially instantaneous reduction of pressure may be enjoyed. The result is that all of the grains are puffed to substantially the same degree. I have found that when a secondary supply of fluid is not used, those grains which are remote from the discharge end of the chamber are puffed to a lesser degree than those which are close to the discharge opening, because of the somewhat slower pressure reduct ion to which the former are subjected.

A second advantage of applying a secondary supply of fluid is that the fluid so supplied entrains any groats which might have a tendency to remain in the chamber after discharge, thereby effecting complete evacuation of the chamber and increasing the efiiciency and economy of the operation.

In the accompanying drawings, I have illustrated one form of apparatus which may be employed for carrying out my method. Referring to the drawings, reference numeral l0 designates generally a carriage or cradle on which the device is mounted and which consists of a pair of standards H adapted to be firmly bolted or otherwise secured to a floor or other foundation. Said standards are connected to each other by means of a tie-plate l2. To provide a convenient means for pivotally mounting the pressure chamber, the top portion of each standard II is in the form of a pair of plates l3, having central adjacent semi-circular portions defining bearings H.

The pressure chamber as shown in detail in Figs. 2 and 5, consists of a relatively heavy cylindrical member l5, having a closed end l6 and an open end 11. Member I5 is preferably made of cast steel and cast integrally therewith is a pair of trunnions l8 adapted to be positioned within the bearings M to pivotally support the pressure chamber for rotational movement in a vertical plane. The chamber is rotated onsaid trunnions by manually manipulating lever i811. Positioned within member l5 and concentric therewith is a tubular lining member 13 preferably made of non-oxidizing material such as stainless steel, Monel metal, or the like. One end of member i9 is spaced 8. short distance from the closed end ii of member l5, and the other end projects through the open end of said member. The projecting portion is somewhat enlarged andis spherically ground to provide a valve seat 20. The wall of member I5 is increased in thickness at the open end for the purpose of strengthening the same. The inner end of tube i9 is counterbored to provide a shoulder 22 against which is positioned a disc or diffusion plate 23, having a plurality of apertures 24, which as shown, are in the form oi slots. The difiusion member is in effect a partition which divides the pressure chamber into two communicating chambers, the forward one of which serves as a treating chamber and the other as a fluid-receiving and storing chamber.

Communication is aflorded to the interior of the pressure chamber through passageway 25 formed axially of one of the trunnions l8, and passageway 26 formed in the wall of member 45. One end of passageway 26 communicates with passageway 25 and the other end terminates adjacent the closed end iii of the chamber. Passageway 25 is in communication with a source of supply of fluid under pressure through nipple 21 and conduit 28. Nipple 21, which is stationary, is shown as having a screw-threaded end extending into passageway 25 and engaging screw threads formed in the wall thereof to permit of relative angular movement between said nipple and trunnion I8 as the pressure chamber is rotated about said trunnion. The admission of fluid to the pressure chamber is controlled by manually operated valve 29. The closed end ii of the chamber is provided with an outlet 30 controlled by a valve 3i.

Journalled in a pair of spaced plates 32 formed integrally with member I5 is a valve yoke 33, which consists of a pair of vertical plates 34 joined at their lower ends by straps 35 and at their top portions by member 36. Extending between plates 34 and journaled therein is a bar 39 having reduced end portions 40, and having a centrally positioned and threaded aperture 4| adapted to be brought into alignment with the longitudinal axis of the pressure chamber when the yoke is in the valve-closing position. The open end ll of the pressure chamber is closed by a spherically ground valve or closure member 42 carried by a threaded valve spindle 43, which is threaded through aperture 4! and held in position by means of lock-nut 44. Valve 42 is connected to spindle 43 by means of a ball and socket joint 46. Valve 42 is provided with leakport 42a.

Mounted on member 15 and preferably cast integrally therewith, is a vertical lug 58, having an aperture 5| in which is positioned a shaft 52. The ends of shaft 52 are reduced to provide a pair of aligned cranks 53, which are eccentrlcally arranged with respect to said shaft. A rod 54 is mounted on each crank 53. Said rods extend in substantially parallel relationship and at their free ends support a detent block 56 having a detent 51 formed in its under surface. A lever or handle 58 is mounted on one of said cranks in such a manner as to rotate therewith. Intermediate their ends rods 51 are joined by a shaft or pin 59 on which is mounted a cam 80, which is adapted to be rotated by cam handle ii. Adjacent its open end, member l5is provided with an integral vertical portion 63 provided with teeth 64 and 65 and an intermediate flat surface 68. Cam 6!! is provided with a pair of teeth 61 and 53 which are adapted to engage with teeth 53 and 65 respectively when the handle Si is rotated in a counter-clockwise direction (looking at Figs. 1, 2 and 4) to positively lock rods 54 and detent 51 in their lowermost position, illustrated in Fig. l. A spiral spring 69, having one end secured to the shaft 59 and the other end hooked .over a pin 69a carried by one of the rods SI, tends to hold the cam in this position. i The cam surface, indicated by the numeral 10, is so designed that, upon rotation of the handle Si in the clockwise direction, it will coact with surface 45 to elevate the rods 54 and detent 51 to their upper, or closure-releasing position, illustrated in dotted linesin Fig. 2. A stop member H is provided in the upper portion of member 63, to limit the upward movement of rods 54. Looking at Fig. 2, it .will be noted that detent 51, when in its lower position, is in the path of travel of projecting portion I2 of member 35; The upper surface of portion 12 is inclined as indicated at 13, to permit the detent to ride over said surface when the valve is being closed.

A pair of friction plates 15, carried by lugs I5 depending from casting i5 are provided for frictional engagement with the vertical ends of strap 35 during the opening movement of the valve to dissipate some of the energy of the valve and associated mechanism. The bearing force exerted by plates 15 on strap 35, and consequently the amount of energy dissipated through frictional.

engagement of the plates with said strap, is regulated by adjustment of a pair of springs, one of which actson each plate. In Fig. 8 I have shown one such spring. Plate 15 is loosely supported by pin 18 for limited movement. A hollow boss or lug 19 extends from member 16 and within said boss is a thrust member 8!! bearing directly on plate 15. Threaded through the open end of said boss is an adjusting screw 8i, and positioned between said screw and said thrust member isa helical spring 82. Spring 82 tends to hold plate 15 in the dotted line position shown in Fig. 8. Obviously, adjustment of screw 8| will vary the tension of spring 82 and will definitely affect the magnitude of the energy dissipated through frictional engagement of the strap with plates 15, as the valve yoke passes between said plates during the opening movement. The residual energy is absorbed by a resilient member, preferably a solid block of rubber which is positioned in the path of travel of the valve yoke. As shown, a pocket 83 is formed in the tie-plate l2 and a solid block of resilient material 84 is placed therein at such an angle that its upper surface isparallel to the contacting surface of the valve yoke at the instant of contact. Block 84 serves as a cushion stop member to yieldingly limit the downward movement of the valve mechanism. Springs 82 may be so adjusted that the impact of the valve mechanism on block 84 will be relatively light and the valve mechanism will come to rest thereon. Or, if desired, the adjustment of springs 82 may be varied to permit an impact of sufficient magnitude to cause the return of the valve mechanism, due to the resiliency of block 84, to a position between plates 15 where it will be held by said plates in convenient position for subsequent manual closing.

The pressure chamber may be locked in the horizontal position to prevent accidental rotation by the reaction incidental to sudden pressure release by a pair of rods 86, one of which is mounted in each standard H. as shown in Figs. 1 and 7. The forward ends 81 of the rods are reduced in size to fit through apertures formed in the forward legs of standards II, and are provided with flat under surfaces adapted, when the gun is in the horizontal position, to rest upon the upper surfaces ofiv plates 58, one of which extends from each side of casting l5, thus locking the chamber in the horizontal position. The rods are urged in the forward or looking position by springs 90 acting on collars 9!, there being one spring and one collar mounted on each rod. The rods are withdrawn from the locking position by depressing either one of a pair of foot pedals 82, eachof which forms an arm of a bell crank lever 53, one of said levers being connected to each rod through a link 54. Both pedals are mounted on shaft 95 for simultaneous rotational movement. Thus, depression of either pedal will release both rods -and permit the chamber to be rotated to the vertical position for loading.

In operation the pressure chamber is rotated on 'trunnions l8 by'means of lever Ila until it assumes the vertical or loading position illustrated by dotted lines in Fig. 4. In this position 51 in the downward p0 ons.- Shaft 52 is then rotated in the clockwise direction by means of lever 58, causing rods 54 to be'moved to the right (looking at Fig. 2). This movement of rods 54 will cause detent 51' to be brought into engagement with projection 12. As further pressure is applied to the lever 55, valve 42 obviously will be brought into tight engagement with valve seat- 20. The ball and socket connection permits lim- Because of. the swivel mounting of i can be adjusted by loosening lock-nut 44 and turning spindle 43. Valve 3| may be opened at this point to drain off any condensate which may be present in the chamber, or, if the chamber is cool, to permit the fluid to .blow through outlet 30 to raise the temperature of the chamber and the chamber wall. closed, valve 29 is opened to admit fluid under pressure to the chamber. The fluid enters the fluid-receiving zone of the chamber from passageway. 26 and is broken up into a series of'fine streams by diffusion member 23. As the fluid progresses toward the forward end of the chamber, it forces the air contained therein through leak-port 42a, to the atmosphere. It is highly desirable that, in apparatus of the character in question, all of the air be removed from the chamber to prevent the formation of air pockets in the zone occupied by the cat groats.

The chamber is then rotated to the horizontal or discharge position shown in Figs. 2 and 4. After the material has remained for the necessary period of time, valve .29 is closed and handle BI is rotated in the clockwise direction. (looking at Fig. 2), causing teeth 61 and 68 to become free from engagement with teeth 54 and G5, and causing rods 54 to be elevated by the action of cam After valve 3| has been oats by using as a fiuid medium super-heated steam at approximately two hundred pounds gauge pressure, and carrying from 50 to 200 F. of superheat. The steam is admitted to the treating chamber in the diffused condition, as by dividing it into a plurality of fine streams, after the groats have been placed in the chamber and the latter tightly closed. The greats are then permitted to remain in the chamber for a period of from one and 'a half to two minutes. The length of time of treatment, the degree of superheat of the steam and its pressure depend upon the moisture content of the .groats and can be readily determined by a few tests under varying degrees of super-heat for different periods of time.

The advantages of my invention will now be fully appreciated. Duringthe period the oat groats remain in the chamber, theirpores be-. come thoroughly impregnated with superheated steam. When the pressure'is suddenly released, the steam escapes from the pores with sumcient vigor to cause disruption of the cell walls and enlargement or puffing of the groat. This action is probably enhanced by the flashing into steam of a large portion of the natural moisture content of the groat, resulting in partial dehydration of the groat. Obviously, the less suddenly the pressure is released, the less vigorously the steam will tend to escape from the interior of the great, and the less the size of the great will be increased. As the groats remote from the open end of the chamber must travel the entire length of the treating chamber before they reach the atmosphere, they would normally be subjected to less sudden pressure reduction than those adjacent the open end of the chamber. According to my invention, the reduction of pressure within the treating zone of the chamber is retarded ina degree by the steam stored in the fluid-receiving zone which expands into the treating zone as the pressure'therein tends to diminish. Although the actual period of time required for complete reduction of pressure is pro-' longed .but a traction of a second by said secondary steam supply, it assists in permitting substantially uniform puffing of the entire mass of groats. Also, as mentioned above, as said secondary steam supply rushes toward the open end of the chamber, it carries with it anyugroats which may tend to remain in the chamber.

A further advantage obtained when my process is employed for treating foodstuffs having-a delicate flavor is that, because of the extremely short period of time required for treatment, and of the manner in which the steam issupplied to the treating chamber, that is, in the diffused condition, the flavor of the substance undergoing treatment is not impaired.

In the above I have described one manner in which my invention may be carried out. Many modifications will occur to those skilled in the art.- For example, the diffusion of the fluid may be accomplished in many different ways. The secondary fluid supply may be stored outside the chamber, as well as within the confines of the chamber. The particular fluid medium employed may be varied to suit different conditions. When it is desired to pufi or disintegrate at room temperature, carbon dioxide gas, compressed air, or any suitable fluid medium may be employed. It is the intent that this patent shall cover all such modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A method of manufacturing ready-to-eat puffed oats possessing a commercially useful shelf-life which comprises placing a quantity of cats in a closed chamber having an inlet at one end and an outlet at the other, admitting to said chamber, substantially simultaneously over its entire cross-sectional area,'superheated steam so as to expel therefrom the therein contained air, closing said outlet to build up a pressure in the chamber to cook the raw oats 'without deteriorating the'oil contained in them, and suddenly releasing the pressure while admitting a secondary supply or" superheated steam under pressure to said chamber.

2. The method of preparing a ready-to-eat food'product possessing a commercial shelf-life from oat grains by the explosion process which consists in placing a body of raw.oat grains to be treated in a pressure chamber, uniformly subjecting said body of raw oat grains throughout substantially its entire cross-sectional area to the ac on of steam under superatmospheric pressure an carrying 50 to 200F. superheat for a period not in excess of two minutes thereby simultaneously uniformly cooking the oat grains without decomposing the natural oil content thereof, and then suddenly releasing the pressure in said chamber to expel and substantially uniformly expand the cat grains.

3. The method of preparing a ready-to-eat food product possessing a commercial shelf-life from oat grains by the explosion process which consists in placing a body of raw oat grains to be treated in a pressure chamber, uniformly subjecting said body of raw oat grains throughout substantially its entire cross-sectional area to the action of superheated steam under superatmospheric pressure for a period not in excess of two minutes thereby simultaneously uniformly cool:- ing the cat grains without decomposing the natural oil content thereof, and then suddenly releasing the pressure in said chamber to expel and substantially uniformly expand the oat grains.

i. The method of preparing a ready-toeat food product possessing a commercial shelf-life from oat groats by the explosion process which consists in placing a body of raw oat groats in a pressure chamber, uniformly subjecting said body of raw oat groats throughout substantially its entire cross-sectional area to the action of superheated steam under superatmospheric pressure to simultaneously uniformly cook the oat groats over said cross-sectional area without decomposing the natural oil content thereof, and then suddenly releasing the pressure in said chamber to expel and substantially uniformly expand the oat groats.

5. The process of producing substantially nonrancidifiable expanded oats which comprises confining the oats in a closed air-containing space, expelling the air from said space by means of a mass of' highly heated steam introduced substantially uniformly over the cross-sectional area of said space so as rapidly to envelop the oats substantially uniformly with a non-oxidizing heated atmosphere maintained under a superatmospheric pressure, maintaining the temperature sufficiently high to cool; the cats in a period of time not substantially exceeding two minutes, whereby the fatty constituents of the cats remain unaffected, and then suddenly releasing the pressure.

' WILLIAM J. PLEWS. 

